What Is Fracking— And Why Is It So Controversial?
Hydraulic fracturing, also known as fracking, is a technique that involves the fracturing of bedrock formations by a pressurized liquid. Namely, the “fracking fluid” is a combination of water, sand, and chemicals injected underground at a very high pressure to crack open hard rock layers to release the oil and/ or gas trapped inside.
Fracking is not a new technique. In fact, this procedure began as an experiment in 1947, and its successful application followed a few years later in 1950. This technique for extracting gas and oil has become more widespread in recent years. In the mid-2000s, many companies discovered that the extraction would be cost-effective by combining fracking with methods such as horizontal drilling. This “fracking boom” has reshaped the energy landscape, especially in many states including North Dakota, Texas, and Pennsylvania. Since 2012, approximately 2.5 million jobs have been created worldwide on oil and gas wells, 1 million of those jobs are within the U.S.
On the one side, fracking creates jobs, boosts manufacturing, and reduces the amount of coal used in other drilling processes. However, many opponents argue that this industry has lax regulations, increases air pollution, contaminates groundwater and surface water, and creates human health problems.
How Does Fracking Work?
The procedure of hydraulic fracturing and horizontal drilling to extract oil or gas is a complex process that involves several steps. The basic fracking operation begins by drilling a hole called a “wellbore” that extends up to the layer of gas-rich shale. The shale layer can be as deep as 5000 feet (approx. 1.5 km), and drilling can last up to one month. In this step, the well is lined with a steel casing to prevent groundwater contamination in the area. Once the drill gets to the shale layer, it slowly turns and starts drilling a horizontal well along the rock. The next step involves puncturing tiny holes in the horizontal section of the shale layer with a “perforating gun” loaded with explosive charges. The fracking fluid is then pumped into the well at extremely high pressure and penetrates through the tiny holes, which cracks the shale. The sand from the mixture holds the cracks open while the chemicals extract the natural gas and allow it to travel up the pipe. Once this stage is finished, the water and chemicals flow back out of the well and are adequately removed for disposal or treatment.
Via pipe network, the gas is shipped to consumers. Typically, a well has the capacity to produce gas for 20-40 years, a period during which thousands of cubic feet of gas each day are extracted. Depending on the geology of the region and the technology used, the process of fracking has many variations.
How Has Fracking Changed Our Future?
As previously mentioned, natural gas can be used as a substitute for coal. But, will this procedure outweigh the gains from using a cleaner fuel and minimize environmental damage?
Fracking is a high-risk procedure, and its benefits do not outweigh its consequences. Why? There is a common misconception that natural gas is a cleaner alternative to coal. Coal produces harmful byproducts, including large amounts of soot compared to natural gas. Still, Intergovernmental Panel on Climate Change (IPCC) reports that the carbon content of natural gas – methane is 34 times greater than that of carbon dioxide over a 100-year time scale. The Environmental Protection Agency (EPA) reported that the global warming potential of methane is 21 times greater than that of carbon dioxide over a 100-year time scale (EPA, n.d.).
Fracking also poses a threat to the environment, starting with the fracking fluid. Based on the rock type and the specifics of the site, different chemicals are added for various purposes. For example, acids are used for dissolving minerals to ease the fossil fuel flow; biocides are added to eliminate bacteria; gelling agents are used to carrying proppant into fractures; corrosion inhibitors are added to protect the steel parts of the well. EPA identified 1084 different chemicals used in the fracking process between 2005-2013, including methanol, ethylene glycol, and propargyl alcohol, most of which are hazardous or potentially hazardous to human health, or their impact is unknown (Denchak, 2019).
Fracking also poses a risk to groundwater resources. The landscape in North America has been altered by directional drilling and high-volume hydraulic fracturing (HVHF) due to increased oil and gas production. Since 2017, the Pennsylvania Department of Environmental Protection (PADEP) has issued 302 letters to homeowners documenting incidences of presumed groundwater contamination from oil and gas development (Barth-Naftilana et al., 2018). At that time, there were 10,908 unconventional wells drilled in Pennsylvania. There are disagreements regarding the causes of water-quality impairments, which require additional observations to understand and resolve the issue.
Other issues tied to fracking include:
- Wastewater disposal issues;
- High water usage (EPA estimated that in 2010, approximately 70-140 billion gallons of water were used to fracture 35,000 wells in the U.S., which is equal to the annual water consumption of 40-80 cities, each with 50,000 citizens);
- Contamination of drinking water (EPA linked fracking with local contamination of drinking water in many states, including Pennsylvania, Colorado, Ohio, and Wyoming);
- Poor infant health (Science Advances published a study which found that babies born within half a mile radius of a fracking site have significantly higher chances of low birth weight and are more likely to suffer from poor health).
- Habitat destruction (creation of fracking wells takes place at the expense of the destruction of local habitats; as a result of fracking, in Wyoming, between 2001 and 2010, the reduction of mule deer’s habitat resulted in a decrease of 56% of their population);
- Earthquakes (According to the United States Geological Survey (USGS), Oklahoma has the most induced earthquakes in the U.S., and 2% can be linked to fracking. In 2018, the state of Texas experienced the largest hydraulic fracturing induced earthquake with a magnitude of 4.0).
Technologies and Methods That Can Make Fracking Cleaner
While fracking is not the most sustainable and eco-friendly replacement for coal, some technologies and methods can make this procedure cleaner. Traditional fracking systems operate with large quantities of water; therefore, usage of water-free fracking systems can gather the same results as using water. For example, gelled fluid containing propane, uses one eighth of the liquid traditionally required and pumps the liquid at a substantially lower rate. Another option is to replace freshwater with recycled water or brine. This switch will conserve fresh water and, at the same time, will reduce the water pollution caused by traditional fracking systems.
Fracking produces high amounts of wastewater, containing chemically treated water. Although the wastewater is shipped to underground storage facilities, the introduction of wastewater purification could reduce potential pollution and allows the water to be reused in the fracking process.
Methane leaks are one of the primary concerns of fracking. The most effective methods in reducing methane leaks are using an infrared camera to detect leaks at fracking sites and replacing traditional pressure-monitoring pneumatic controllers with lower-bleed designs. Interestingly, an article by National Geographic indicated that replacing those controllers could reduce methane leaks by up to 35 billion cubic feet annually (Kiger, 2014).
Sources:
Barth-Naftilana, E., Sohnga, J., & Saiersa, J.E. (2018). Methane in groundwater before, during, and after
hydraulic fracturing of the Marcellus Shale. Proceedings of the National Academy of Sciences, 115(27). Retrieved from: https://www.pnas.org/doi/pdf/10.1073/pnas.1720898115
Denchak, M. (2019). Fracking 101. Natural Resource Defense Council. Retrieved from: https://www.nrdc.org/stories/fracking-101
Environmental Protection Agency. (n.d.). Understanding global warming potentials. EPA. Retrieved from: https://www.epa.gov/ghgemissions/understanding-global-warming-potentials
Kiger, P. J. (2014). Green fracking? 5 technologies for cleaner shale energy. National Geographic. Retrieved from: https://www.nationalgeographic.com/science/article/140319-5-technologies-for-greener-fracking